There is known a sensor unit, which includes a Hall IC having sensing elements for sensing a magnetic flux. For example, JP5067676B2 (corresponding to US 2011/0221432 A1) discloses a sensor unit that has two Hall ICs. One of the Hall ICs is placed at a front surface of a circuit board of the sensor unit, and the other one of the Hall ICs is placed at a rear surface of the circuit board.
In JP5067676B2 (corresponding to US 2011/0221432 A1), since the Hall ICs are mounted to the front and rear surfaces, respectively, of the circuit board, a reflow process needs to be performed twice.
In a case where two ICs, such as small outline package (SOP) type ICs, each of which has terminals at each of two sides of the IC, are placed adjacent to each other on a common surface of a circuit board, there will be a possibility of pin-to-pin short circuit between the ICs.